Re: oracle cause "load" on OS level very high.

> 40 DOES not mean 40 processes.
> Itis the "load" on Unix system.
> Actually at that moment, it say it is running 970 processes in the
> system.
>

hehe - a load of 40 *DOES* actually mean 40 processes in *RUNNABLE* state :-)
and they are all queued up to run on your tiny CPU ... hence the name runqueue

If you don't know what the process states runnable, sleep, zombie, pre-emted etc mean
you can start by reading up on unix...
may I suggest the following books :
"The Design of the Unix operating system by Maurice J Bach" http://www.amazon.co.uk/exec/obidos/ASIN/0132017997/ref=sr_aps_books_1_1/202 -3322413-4230252
Well known excellent book - must read !
"Optimizing Unix for performance by amir h majidimehr" http://www.amazon.co.uk/exec/obidos/ASIN/0131115510/qid%3D1028917178/202-332 2413-4230252
Unknown book but it kicks ass - Unix DBAs -> buy it !

But of course - you could always start by typing "man uptime" or "man top" at your prompt and it'll explain *load* for you : "The uptime command prints the current time, the length of time the system has
been up, the number of users online, and the load average. The load average is
the number of runnable processes over the preceding 5-, 10-, 15-minute intervals. The output of the uptime command is, essentially, the heading line
provided by the w command."

"Dominica Leung" <dominica_l_at_yahoo.com> wrote in message news:5f8af180.0208081730.1ccc1c85_at_posting.google.com...
> Hi,
>
> 40 DOES not mean 40 processes.
> Itis the "load" on Unix system.
> Actually at that moment, it say it is running 970 processes in the
> system.
>
> You know what, I am NOT USING MTS,
> but I should,
> let me ask you this, if
> I have 970 processes, how many dispatches should I use??
>
> You are right, it could has so many FACT to have load that high.
> But you know what, I think this company is really MAX out this
> TINY POOR little machine.
> They do 582 select per second. It is a lot.
> Thanks for your help tough.
>
> my next project is to setup CONNECTION manager, I don't know how yet.
>
> Dominica
>
>
> ==============
>
> "koert54" <nospam_at_spam.com> wrote in message
news:<4Qd49.53393$8o4.7093_at_afrodite.telenet-ops.be>...
> > if I'm not mistaken the 'load' is the number of runnable processes ...
so if
> > it peeks to 40 it means
> > 40 processes are runnable at that moment ... this could mean that :
> > - someone is using parallel query (pq slaves) ?
> > - someone wrote some stupid program that connects multiple times
> > concurrently is a short amount of time ?
> > - dbwriter is using dbwriter slaves ? multiple arch slaves ?
> > - a process is spawning a hugh amount of threads ?
> > - combination of above ...
> > - other reason :-)
> >
> > My experience is on boxes that show very high runqueues and peaks of
high
> > runqueues, PQ is being abused - parallel processing
> > is not always faster ... one time a saw a box with a runqueue (load) of
80
> > to 100 ... reason was a high parallel degree clause on most tables -
> > lowering PQ -> low runqueue -> lower overhead, context switches ->
increase
> > performance ...
> > My experience is, depending on number of CPUs, a runqueue/load of 2 to 3
> > times number of CPUs is a performance limiet...
> >
> > "Dominica Leung" <dominica_l_at_yahoo.com> wrote in message
> > news:5f8af180.0208061359.6cac32d6_at_posting.google.com...
> > > Hi All,
> > >
> > >
> > > I am wondering whether anyone seen this kind of situation
> > > before in Performance tuning aspect.
> > >
> > > I am (this company AA) is running oracle 8.0.6.2
> > > 32 bits on
> > > solaris 2.6 OS.
> > >
> > > There is very strange thing happen.
> > > When I do a "top",
> > > everyday at 2:30 pm and 2:45PM
> > > (there are some cronjob from Engr dept doing select and
> > > update)
> > > the "load" from the "top" command, will be 40.00.
> > > This is very high, normal machine is 4 or 5.
> > >
> > > =========================================
> > >
> > > last pid: 8806; load averages: 40.00, 8.57, 9.67
> > > 14:50:39
> > > 928 processes: 923 sleeping, 2 running, 3 on cpu
> > > CPU states: 32.9% idle, 54.0% user, 13.0% kernel, 0.0% iowait, 0.0%
> > > swap
> > > Memory: 4096M real, 133M free, 282M swap in use, 1254M swap free
> > >
> > > =================================================
> > > It only spike up for 3 or 4 minutes.
> > >
> > > When I do top, I only see the
> > > PID is 25923, which is
> > > the oracle 25923 1 0 Jun 29 ? 1031:47 ora_dbw0_USRDEV
> > >
> > > My question is ?
> > > 1) is there anything I should look??
> > > I have looked at V$lock, v$transaction at that time,
> > > there is NO PROCESS waiting for transaction, only 14 locks in the
> > > whole system.
> > >
> > > Curious how to improve it, look like database writer is very busy.
> > >
> > >
> > > I know people might told me "this machine is MAX out" in the
> > > capacity. But I hope there is something I could do about it.
> > >
> > >
> > > Thanks,
> > >
> > >
> > > Dominica
Received on Fri Aug 09 2002 - 13:25:36 CDT